1. Field of the Invention
This invention relates to musical instruments. Specifically, and not by way of limitation, the present invention relates to a laser pick-up for use on a stringed musical instrument.
2. Description of the Related Art
There are a wide variety of stringed musical instruments. One very popular stringed instrument is an electric guitar. A conventional electric guitar is a type of guitar which utilizes pick-ups to convert the vibration of its steel-cored strings into an electrical current. The electric current is then amplified by an instrument amplifier and outputted as sound through a speaker. Oftentimes, the signals emanating from the guitar are electronically altered with guitar effects, such as reverb or distortion.
Electric guitars make comparatively little audible sound in comparison to an acoustic guitar because the strings of an electric guitar have their strings plucked. Instead, the movement of the strings generates or induces a very small electrical current in the magnetic pick-ups. The magnetic pick-ups are magnets which are wrapped with coils of very fine wire. The induced current is then sent via a wire to an amplifier. The induced current is dependent upon such factors as the density of the string or the amount of movement over the pick-ups. The vibration of the strings is, in turn, affect by several factors, such as the composition and shape of the body of the guitar.
There are also some hybrid electric-acoustic guitars which are equipped with additional piezoelectric pick-ups or transducers that sense mechanical vibrations from the body of the guitar. Because in some cases it is desirable to isolate the pick-ups from the vibrations of the strings, a guitar's magnetic pick-ups are sometimes embedded or “potted” in epoxy or wax to prevent the pick-up from having a “microphone” effect.
Because of their natural inductive qualities, magnetic pick-ups suffer from the disadvantage of picking up ambient and usually unwanted electromagnetic noises. The resulting noise, an unwanted “hum,” is particularly strong with single-coil pick-ups, and aggravated by the fact that very few guitars are correctly shielded against electromagnetic interference. The most frequent cause of this hum is the strong 50 or 60 Hz component that is inherent in the frequency generation of current within the local power transmission systems. As nearly all amplifiers and audio equipment associated with electrical guitars relies on this power, there is, in theory, little chance of completely eliminating the introduction of unwanted hum.
Double-coil pick-ups, also known as “humbuckers,” were invented as a way to reduce or counter the unwanted ambient hum sounds. Humbuckers have two coils of opposite magnetic and electric polarity. Thus, electromagnetic noise hits both coils, which should cancel itself out. The two coils are wired in phase, so the signal picked up by each coil is added together. This creates the richer, “fatter” tone associated with humbucking pick-ups. A pick-up is needed which is not susceptible to picking up unwanted ambient noises.
Thus, it would be advantageous to have a pick-up for use on stringed instruments which generates signals from vibrating strings of a musical instrument without picking up unwanted ambient noise. It is an object of the present invention to provide such an apparatus and method.